Herniation of the cauda equina into the facet joint through a pseudomeningocele: A case report and literature review

BACKGROUND: Incidental durotomy is a well-known complication of spinal surgery. It can lead to persistent cerebrospinal fluid leakage resulting in significant secondary complications. Here, we present a case in which the cauda equina herniated into a pseudomeningocele that penetrated a facet joint, leading to lower extremity radiculopathy warranting surgical correction. CASE DESCRIPTION: One year ago, a 67-year-old male underwent a partial left L4-L5 laminectomy. At surgery, a durotomy was repaired with a nylon suture and reinforced with a fat patch. He subsequently presented with severe left lower extremity radiculopathy and a partial cauda equina syndrome. On MR, the cauda equina had herniated into a pseudomeningocele that penetrated the left facet joint. Once the defect was repaired at surgery, the patient’s symptoms improved. CONCLUSION: It is critical to correctly repair an intraoperative durotomy to avoid further neurological deficits that may include cauda equina herniation into pseudomeningoceles penetrating facet joints.